The applicants propose to develop an optical biomedical imaging technique that records real-time video biological tissue, without computed tomography, using compact light sources. This technique uses a newly developed adaptive holographic film that performs as a coherence filter on a video camera, making it possible to image up to 15 mean-free-scattering paths into strongly scattering living tissue near- infrared light (up to 100 um deep into tissue while maintaining 10 um spatially high resolution). The capabilities of the technique will be benchmarked by imaging the three-dimensional structure multicellular spheroids composed of normal and neoplastic cells (tumor spheroids). The spheroids are balls of cells that may be easily cultured in vitro and used to simulate the optical properties of various tissues and nodular tumors. If successful, the proposed research has many biomedical applications. For instance, this technology may be used for dermatological lesion scanning (skin cancer), burn assessment, investigation of internal surfaces through endoscopes or catheters using imagin bundles, and intra-operative procedures giving a physician immediate video images of tissue beneath the surgical surface. Because of the immediate high-speed nature of direct imaging, this technology will be particularly attractive for fast dynamic studies and making movies of processes inside tissue such as portions of the cardiovascular system requiring high time resolution, or for metabolic imaging of tumors and the rapid uptake of tagged optical markers. This optical tissue imaging technology will be unique in its combination of high time resolution with high spatial resolution, and therefore represents a unique biomedical imaging technology with significant potential for down-stream development for cancer imaging.